Amicable orthogonal designs have renewed interest because of their use in mobile communications. We show the existence of strong amicable orthogonal designs, AOD(n : 1, n − 1; 1, n − 1), for n = p + 1, p ≡ 3 (mod 4) a prime and for n = 2, n a non-negative integer in a form more suitable for communications. Unfortunately the existence of amicable Hadamard matrices is not enough to demonstrate th...

In this paper experimentally, the friction-stir welding of the polypropylene sheets with 40% glass fiber has been investigated. Comparison to other welding methods, the strength of the joint is the most important feature in this process. Many parameters such as tool geometry, rotational speed, linear velocity, and tilt angle are very important as input parameters in this type of welding. Theref...

We propose an algorithm for sequentially constructing non-isomorphic orthogonal designs (including both regular and non-regular orthogonal designs). An essential element of the algorithm is using minimal column base to reduce the computations for determining isomorphism between any two designs. By using this algorithm, we obtain the complete catalogs of n k (k = 2; : : : ; n 1) two-level orthog...

Weifeng Su and Xiang-Gen Xia. 2003. "On Space-Time Block Codes from Complex Orthogonal Designs", Wireless Personal Communications 25: 1–26. A. V. Geramita and J. Seberry. 1979. Orthogonal Designs, Quadratic Forms and Hadamard Matrices. Lecture Notes in Pure and Applied Mathematics, Vol. 43, Marcel Dekker: New York and Basel. V. Tarokh, H. Jafarkhani and A. R. Calderbank. 1999. "S...

In this paper experimentally, the friction-stir welding of the polypropylene sheets with 40% glass fiber has been investigated. Comparison to other welding methods, the strength of the joint is the most important feature in this process. Many parameters such as tool geometry, rotational speed, linear velocity, and tilt angle are very important as input parameters in this type of welding. Theref...

A headspace solid-phase microextraction (HS-SPME), in conjunction with gas chromatography-flame ionization detection for use in the determination of six frequently used glycol ethers at the microg/l level is described. A 75 microm Carboxenpolydimethylsiloxane fiber was used to extract the analytes from an aqueous solution. Experimental HS-SPME parameters such as extraction temperature, extracti...

This paper defines a class of designs which generalise t-designs, resolvable designs, and orthogonal arrays. For the parameters t = 2, k = 3 and λ = 1, the designs in the class consist of Steiner triple systems, Latin squares, and 1-factorisations of complete graphs. For other values of t and k, we obtain t-designs, Kirkman systems, large sets of Steiner triple systems, sets of mutually orthogo...

Craigen introduced and studied signed group Hadamard matrices extensively in [1, 2]. Livinskyi [13], following Craigen’s lead, studied and provided a better estimate for the asymptotic existence of signed group Hadamard matrices and consequently improved the asymptotic existence of Hadamard matrices. In this paper, we introduce and study signed group orthogonal designs. The main results include...