D-optimal designs are n x n ±l-matrices where n == 2 mod 4 with maximum determinant. D-optimal designs obtained via circulant matrices are equivalent to 2-{ v; kl i k2 i k1 + k2 ~(v 1)} supplementary difference sets, where v = ~. We use cyclotomy to construct D-optimal designs, where v is a prime. We give a generalisation of cyclotomy and extend the cyclotomic techniques which enables use to fi...

sleep apnea, and particularly obstructive sleep apnea, is a common disorder that is characterized by a repetitive, partial or complete cessation of air flow, associated with oxyhemoglobin desaturation and an increased effort to breath. in recent years, orthodontists have been interested and involved in the management of this disorder since it has been shown that oral appliance therapy can be an...

background: esophageal cancer is one of the prevalent cancers in east azerbaijan province. the aims of this study are to estimate the survival rate of patients with esophageal cancer by treatment modalities and tumor location, as well as risk factors such as cigarette smoking, family history, age at diagnosis, and gender. materials and methods: in a cross-sectional study we evaluated 142 patien...

Watermark recovery is often based on cross-correlating images with pseudo-noise sequences, as access to un-watermarked originals is not required. Successful recovery of these watermarks is determined by the (periodic or aperiodic) sequence autoand cross-correlation properties. This paper presents several methods of extending the dimensionality of 1D sequences in order to utilise the advantages ...

We define a notion of unitarizability for weight modules over a generalized Weyl algebra (of rank one, with commutative coeffiecient ring R), which is assumed to carry an involution of the form X∗ = Y , R∗ ⊆ R. We prove that a weight module V is unitarizable iff it is isomorphic to its finitistic dual V . Using the classification of weight modules by Drozd, Guzner and Ovsienko, we obtain necess...

We relate the semiclassical asymptotics of the 6j symbols for the quantized enveloping algebra Uq(sl2) at q a root of unity (resp. q real positive) to the geometry of spherical (resp. hyperbolic) tetrahedra.

A sequence a = (a0, a1, a2, · · · , an) is said to be an almost p-ary sequence of period n + 1 if a0 = 0 and ai = ζ bi p for 1 ≤ i ≤ n, where ζp is a primitive p-th root of unity and bi ∈ {0, 1, · · · , p − 1}. Such a sequence a is called perfect if all its out-of-phase autocorrelation coefficients are zero; and is called nearly perfect if its out-of-phase autocorrelation coefficients are all 1...

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...