The effect of squeeze casting process parameters on wear behavior of AC2A aluminium alloy was primarily investigated in this experimental study. Five process parameters, namely squeeze pressure, pouring temperature, die temperature, die material and compression time, each at four levels were chosen and sixteen experimental runs based on L16 orthogonal array were performed. From analysis of vari...

An important question in the construction of orthogonal arrays is what the minimal size of an array is when all other parameters are fixed. In this paper, we will provide a generalization of an inequality developed by Bierbrauer for symmetric orthogonal arrays. We will utilize his algebraic approach to provide an analogous inequality for orthogonal arrays having mixed levels and show that the b...

A novel radio channel compensation method aiming to give optimal calibration for microstrip antenna array systems is presented in this paper, realized for an actual DOA measurement antenna system using microstrip antennas to sample the electromagnetic field, operating at 4.5GHz. This new approach considers mismatch between antennas and channel RF ports, channel transmission inequalities, and al...

Previous studies found that it is easier for observers to spatially update displays during imagined self-rotation versus array rotation. The present study examined whether either the physics of gravity or the geometric relationship between the viewer and array guided this self-rotation advantage. Experiments 1-3 preserved a real or imagined orthogonal relationship between the viewer and the arr...

We show that the generating function of the symmetric group with respect to five particular statistics gives rise to an exponential Riordan array, whose inverse is the coefficient array of the associated orthogonal polynomials. This also provides us with an LDU factorization of the Hankel matrix of the associated moments.

A 10-GHz discrete cylindrical lens array with multiple beams is designed and characterized as a receiving angle-diversity array for wireless communications in a multipath environment. The array also has dual-orthogonal polarization and therefore built-in polarization diversity. The array is designed for wide-angle scanning between 45 and 45 and measured scanning patterns are presented. The pola...

We present a new algorithm and systolic array for adaptive beamforming. Our approach improves on McWhirter's pioneering work in two respects. First, our algorithm uses only orthogonal transformations and this should have better numerical properties. Second, the algorithms can be implemented on one single pxp triangular array of programmable processors that offers a throughput of one residual el...

This paper proposes the circular antenna array to suppress the cochannel interference for multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) modulation systems. The conventional cochannel interference suppression system employs the linear antenna array in the receiver side, and the capability of circular antenna array in suppressing cochannel interference is...