A (symmetric) nested orthogonal array is a symmetric orthogonal array OA(N, k, s, g) which contains an OA(M,k, r, g) as a subarray, where M < N and r < s. In this communication, some methods of construction of nested symmetric orthogonal arrays are given. Asymmetric nested orthogonal arrays are defined and a few methods of their construction are described.

In this paper, a cooperative algorithm to improve the orthogonal space-timefrequency block codes (OSTFBC) in frequency selective channels for 2*1, 2*2, 4*1, 4*2 MIMO-OFDM systems, is presented. The algorithm of three node, a source node, a relay node and a destination node is formed, and is implemented in two stages. During the first stage, the destination and the relay antennas receive the sym...

The concept of a linear ordered orthogonal array is introduced, and its equivalent geometrical configuration is determined when its strength is 3 and 4. Existence of such geometrical configurations is investigated. They are also useful in the study of (T, M, S)-nets.

Preliminary layout design of buildings has a substantial effect on the ultimate design of structural components and accordingly influences the construction cost. Exploring structurally efficient forms and shapes during the conceptual design stage of a project can also facilitate the optimum integrated design of buildings. This paper presents an automated method of determining column layout desi...

two latin squares of order $n$ are orthogonal if in their superposition, each of the$n^{2}$ ordered pairs of symbols occurs exactly once. colbourn, zhang and zhu, in a seriesof papers, determined the integers $r$ for which there exist a pair of latin squares oforder $n$ having exactly $r$ different ordered pairs in their superposition. dukes andhowell defined the same problem for latin squares ...

background: xanthomonas citri subsp. citri (xcc), the causative agent of bacterial citrus canker, has affected citriculture worldwide. varieties of means have been used to minimize its devastating effects, but no attention has been given to bacteriocins.objectives: here and for the first time, we report the isolation and characterization of two novel bacteriocins.materials and methods: secretom...

In order to reduce the influence of mutual interference between signals from different transmitters, novel orthogonal signals are designed for netted radar systems in this paper. Different stepped time interval pulse trains (STIPT) which are orthogonal are designed for spatially separated transmitting nodes. Because of the good autocorrelation and cross-correlation properties, mutual interferen...