A novel algorithm has been proposed for joint angle and frequency estimation based on uniform rectangular acoustic vector sensors array. The joint angle and frequency problem is linked to a parafac quadrilinear model....
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ISBN:
(纸本)9781479951512
A novel algorithm has been proposed for joint angle and frequency estimation based on uniform rectangular acoustic vector sensors array. The joint angle and frequency problem is linked to a parafac quadrilinear model. Exploiting this link, it drives a quadrilinaear decomposition-based joint angle and frequency algorithm. This proposed algorithm has improved angle and frequency estimation compared to ESPRIT method and parafac trilinear decomposition method. Simulation results illustrate performance of this algorithm.
In this study, the issue of two-dimensional direction of arrival estimation in monostatic multiple-input-multiple-output (MIMO) radar with rectangular arrays is studied and an algorithm based on estimation of signal p...
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In this study, the issue of two-dimensional direction of arrival estimation in monostatic multiple-input-multiple-output (MIMO) radar with rectangular arrays is studied and an algorithm based on estimation of signal parameters via rotational invariance techniques (ESPRIT) is proposed. Through the reduced-dimensional transformation and unitary transformation, the proposed algorithm has very low complexity because of the low-dimension and real-valued computations. Meanwhile, the angle estimation performance of the proposed algorithm is improved compared with conventional ESPRIT and Unitary ESPRIT. The real-valued rotational invariance is utilised to achieve automatically paired estimations of the azimuth and elevation angles in monostatic MIMO radar. Error analysis of the angle estimation and Cramer-Rao bound in MIMO radar are derived. Simulation results verify the improvement and usefulness of our algorithm.
Conventional wideband arrays suffer from the implementation of tapped-delay-line processors in the beamforming networks. In this paper, a wideband rectangular array of omni-directional antenna elements is proposed, wh...
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Conventional wideband arrays suffer from the implementation of tapped-delay-line processors in the beamforming networks. In this paper, a wideband rectangular array of omni-directional antenna elements is proposed, which requires no phase compensations and employs a single real multiplier for each antenna element. The desired angle and frequency characteristic of the array are the key parameters of the design of the beamformer. Furthermore, the undesired frequency characteristics of the antenna elements can be compensated by the beamformer as well. The most practical advantage of the array is that the number of antenna elements required for a relatively high fractional bandwidth is much lower than other comparable wideband beamformers. Copyright (C) 2003 AEI.
The effective conductivities (sigma(eff)) of rectangular arrays of aligned spheroids are accurately determined. The array structure is governed by the array aspect ratio (r(a)), inclusion aspect ratio (r(i)), and incl...
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The effective conductivities (sigma(eff)) of rectangular arrays of aligned spheroids are accurately determined. The array structure is governed by the array aspect ratio (r(a)), inclusion aspect ratio (r(i)), and inclusion volume fraction (f). By varying these three parameters, a wide range of array structure can be generated and the effects of the three parameters on the effective conductivities of the array are investigated. The present array is found to be a more efficient structure in utilizing the enhancing or reducing effect of the inclusion, as compared to the simple cubic array of spheres. For cases of equal r(a) and r(i), the effective parallel conductivity (sigma(eff)(=)) increases, while the effective perpendicular conductivity (sigma(eff)(+)) decreases with increasing aspect ratio, but both are only a weak function of the aspect ratio if the reduced conductivity of the inclusion (sigma) is within the range of 0.1-10. At a fixed r(i), sigma(eff)(=) decreases while sigma(eff)(+) increases with increasing r(a). If r(a) is fixed, sigma(eff)(=) increases while sigma(eff)(+) decreases with increasing r(i). For prolate systems (r(i) > 1), sigma(eff)(=) is greater than sigma(eff)(+) for all permissible f if r(i) greater than or equal to r(a), but the magnitude order switches at higher f when r(i) < r(a). As to oblate systems (r(i) < 1), sigma(eff)(=) is less than sigma(eff)(+) for all permissible f if r(i) less than or equal to r(a), but the magnitude order switches at higher f when r(i) > r(a). (C) 1999 American Institute of Physics. [S0021-8979(99)01701-6].
In this paper it is shown that every m x n array in which each symbol appears at most (mn - 1)/(m - 1) times has a transversal, when n >= 2m(3). (c) 2006 Elsevier B.V. All rights reserved.
In this paper it is shown that every m x n array in which each symbol appears at most (mn - 1)/(m - 1) times has a transversal, when n >= 2m(3). (c) 2006 Elsevier B.V. All rights reserved.
A new method of directivity calculations for rectangular arrays composed of subarrays is proposed. The method is based on representation of a double integral on angular coordinates in the form of series of squared Bes...
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ISBN:
(纸本)9781479985579
A new method of directivity calculations for rectangular arrays composed of subarrays is proposed. The method is based on representation of a double integral on angular coordinates in the form of series of squared Bessel functions. As a result of application of the developed technique, an empirical formula for calculation of aperture efficiency for the beams of a multibeam array is obtained.
3D ultrasound imaging with 2D transducer arrays of large number of elements suffers from high hardware and computational complexity. In order to reduce the number of active channels, various sparse 2D array designs we...
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ISBN:
(纸本)9781728145969
3D ultrasound imaging with 2D transducer arrays of large number of elements suffers from high hardware and computational complexity. In order to reduce the number of active channels, various sparse 2D array designs were presented. However, the proposed designs so far have either irregular element distribution that cannot guarantee uniformity among the scan lines or lack of analysis. In this study, a generalized sparse rectangular array (SRA) is presented, and a design rule that avoids common grating lobes of the transmit and receive SRA pairs is derived by analyzing the beam patterns. The continuous wave (CW) and pulsed wave responses of the SRA pairs are simulated to verify the proposed design rule.
In two experiments, rats swain to a submerged platform in one corner of a rectangular or kite-shaped array created by four identical landmarks attached to the walls of a circular pool. After training in the rectangula...
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In two experiments, rats swain to a submerged platform in one corner of a rectangular or kite-shaped array created by four identical landmarks attached to the walls of a circular pool. After training in the rectangular array, rats expressed a preference for the corner in the kite-shaped array that was geometrically equivalent to where the platform was located previously. After training in either array the removal of two landmarks from the rectangular array, or the landmark at the apex of the kite-shaped array, did not affect the control over searching exerted by the remaining landmarks. The results imply that rats use local rather than global spatial representations when searching for a hidden goal with reference to an array of landmarks.
Antenna array of two dipole antennas made of copper has been designed and analyzed for 0.1 THz frequency in this work for element spacing of d=3 lambda 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{w...
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Antenna array of two dipole antennas made of copper has been designed and analyzed for 0.1 THz frequency in this work for element spacing of d=3 lambda 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d=\frac{3\lambda }{4}$$\end{document} and d=lambda\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d=\lambda$$\end{document}, where lambda is the wavelength. Antenna length is lambda 2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{\uplambda }{2 }$$\end{document} and width is lambda 200.\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{\uplambda }{200} .$$\end{document} Range of azimuth angle is [- 180 degrees-180 degrees] and elevation angle is [- 90 degrees-90 degrees]. Variation in correlation of power transmitted from first port to second port (S21) has been analyzed changing tilt variation of second dipole, inter element spacing and frequency. optimization of results antenna gain has been achieved as 5.41dBi and 6.35dBi for element spacing of d=3 lambda 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$d=\frac{3\lambda }{4}$$\end{document} and d=lambda\documentcla
James et al. have introduced a variant of P systems called parallel contextual array insertion deletion P system and studied some of its properties. The family of array languages generated by this variant of PCAIDPS i...
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James et al. have introduced a variant of P systems called parallel contextual array insertion deletion P system and studied some of its properties. The family of array languages generated by this variant of PCAIDPS includes families of array languages like recognisable picture languages (REC) and context-sensitive matrix languages L(CSMG). In this paper we show that another interesting family L(CF : RIR) of Siromoney matrix languages is included in the family of array languages generated by PCAIDPS with two membranes. [GRAPHICS] .
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