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Transversals in long rectangular arrays

DISCRETE MATHEMATICS 2006年第23期306卷 3011-3013页

作者： Akbari, S. Etesami, O. Mahini, H. Mahmoody, M. Sharifi, A. Sharif Univ Technol Dept Math Sci Tehran Iran Sharif Univ Technol Dept Comp Engn Tehran Iran

关键词： transversal rectangular array

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METHOD OF DIRECTIVITY CALCULATIONS FOR rectangular arrayS 10

METHOD OF DIRECTIVITY CALCULATIONS FOR RECTANGULAR ARRAYS

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10th International Conference on Antenna Theory and Techniques (ICATT)

作者： Fedorov, P. N. Cent Res Inst Armaments & Mil Equipment Armed For Kiev Ukraine

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.

关键词： rectangular array multibeam array calculations directivity effective area beam solid angle aperture efficiency

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Analytic Design of Sparse rectangular arrays for 3D Medical Ultrasound Imaging

Analytic Design of Sparse Rectangular Arrays for 3D Medical ...

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IEEE International Ultrasonics Symposium (IUS)

作者： Yoon, Hansol Lee, Sara Kim, Jeongyeon Song, Tai-Kyong Sogang Univ Dept Elect Engn Seoul South Korea

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.

关键词： sparse 2D array rectangular array grating lobe 3D ultrasound imaging

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Design and analysis of MIMO antenna array for TeraHertz communication

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JOURNAL OF OPTICS-INDIA 2024年 1-17页

作者： Sarkar, Pia Saha, Arijit Banerjee, Amit Chakraborty, Vedatrayee BP Poddar Inst Management & Technol Dept Elect & Commun Engn Kolkata India Dum Dum Motijheel Rabindra Mahavidyalaya Kolkata India Bidhan Chandra Coll Phys Dept Microsyst Design Integrat Lab Asansol India

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

关键词： TeraHertz spectrum 6G communication MIMO antenna Dipole antenna Linear array rectangular array

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Parallel Contextual array Insertion Deletion Grammar 19th

Parallel Contextual Array Insertion Deletion Grammar

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19th International Workshop on Combinatorial Image Analysis (IWCIA)

作者： Thomas, D. G. Immanuel, S. James Nagar, Atulya K. Thamburaj, Robinson SIMATS Dept Sci & Humanities Saveetha Sch Engn Chennai 602105 Tamil Nadu India Madras Christian Coll Dept Math Chennai 600059 Tamil Nadu India Liverpool Hope Univ Dept Math & Comp Sci Liverpool Merseyside England

We introduce a new grammar, called parallel contextual array insertion deletion grammar and show that it has a strictly higher generative power than a system generating recognizable 2D-picture language and Siromoney c... 详细信息

ISBN: (纸本)9783030052881;9783030052874

关键词： rectangular array Parallel contextual array grammar Insertion and deletion

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Parallel Contextual array Insertion Deletion P System 18th

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18th International Workshop on Combinatorial Image Analysis (IWCIA)

作者： Immanuel, S. James Thomas, D. G. Thamburaj, Robinson Nagar, Atulya K. Madras Christian Coll Dept Math Madras 600059 Tamil Nadu India Liverpool Hope Univ Dept Math & Comp Sci Liverpool Merseyside England

ISBN: (纸本)9783319591087;9783319591070

We introduce a new P system model called as parallel contextual array insertion deletion P system, based on the modified row and column contextual rules of parallel contextual array grammar. We can generate a family of two-dimensional picture languages using this P system. We discuss some properties of this P system and find its generating power by comparing this new family of languages with that of certain other well known families of two-dimensional picture languages.

关键词： P system rectangular array Parallel contextual array

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Parallel Contextual array Insertion Deletion Grammar and (Context-Free : Context-Free) Matrix Grammar 20th

Parallel Contextual Array Insertion Deletion Grammar and (Co...

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20th International Workshop on Combinatorial Image Analysis (IWCIA)

作者： Jayasankar, S. Thomas, D. G. Immanuel, S. James Paramasivan, Meenakshi Robinson, T. Nagar, Atulya K. Ramakrishna Mission Vivekananda Coll Dept Math Chennai 600004 Tamil Nadu India Saveetha Sch Engn Math Div Dept Sci & Humanities Chennai 602105 Tamil Nadu India Univ Trier Dept Comp Sci Trier Germany Madras Christian Coll Dept Math Chennai 600059 Tamil Nadu India Liverpool Hope Univ Dept Math & Comp Sci Liverpool L16 9JD Merseyside England

ISBN: (纸本)9783030510015;9783030510022

Siromoney et al. introduced Siromoney matrix grammars (1973) which are of sequential-parallel type in the sense that first a horizontal string of nonterminals is derived sequentially by applying the horizontal production rules and then vertical productions are applied in parallel to get the intended two-dimensional picture. In 1999, Radhakrishnan et al. introduced and studied a variant of Siromoney matrix grammars called (X:Y)MG where X, Y is an element of {Context - Free(CF), Regular(R)}. James et al. in 2018 introduced Parallel Contextual array Insertion Deletion Grammar (PCAIDG) to generate two-dimensional array languages using insertion and deletion operations and parallel contextual mappings. In this paper, we prove that this family of languages generated by PCAIDGs properly includes the family (CF : CF) ML.

关键词： rectangular array Parallel contextual array grammar Insertion Deletion

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Parallel contextual array P systems

Parallel contextual array P systems

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2014 Asian Conference on Membrane Computing, ACMC 2014

作者： Immanuel, S. Thomas, D. Thamburaj, Robinson Nagar, Atulya Department of Mathematics Madras Christian College India Department of Mathematics and Computer Science Liverpool Hope University Liverpool United Kingdom

ISBN: (纸本)9781479980123

We introduce new P system models, called as external and internal parallel contextual array P systems, based on the external and internal parallel contextual array grammars. We can generate rectangular arrays using these P system models with the help of external or internal parallel row and column contextual array rules. We discuss some properties of these P systems and compare them with certain other array generating P systems. © 2014 IEEE.

关键词： P system parallel contextual array grammar rectangular array P Blood-Group System rectangular array Parallel Lines Phosphorus arrays

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Low-Complexity Propagator Based Two Dimensional Angle Estimation for Coprime MIMO Radar

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IEEE ACCESS 2018年 6卷 13931-13938页

作者： Li, Jianfeng Jiang, Defu Hohai Univ Coll Comp & Informat Array & Informat Proc Lab Nanjing 211100 Jiangsu Peoples R China

The problem of 2-D angle estimation for coprime multiple-input multiple-output (MIMO) radar is considered, and a low-complexity propagator based method is proposed. Coprime MIMO radar is configured with transmit and receive rectangular arrays, where transmit array has NxQ elements while receive array has MxP elements (M is coprime to N while P is coprime to Q). Based on the uniformities of the arrays, unitary transformation is exploited to transform the complex data into real-valued one, and then the signal subspace is obtained from a low-complexity propagator matrix, which requires neither eigenvalue decomposition nor pseudo inversion. Thereafter, automatically paired two pairs of coprime parameter estimations can be acquired based on the rotational invariance within the signal subspace. Finally, unique 2-D angle can be estimated from the coincide result of the coprime estimations. Due to the real-valued propagator based method, the proposed method has low complexity, but it can achieve better angle estimation results than conventional methods. Theoretical analysis of the method is derived, and simulation results are presented to verify the effectiveness of the proposed approach.

关键词： Coprime MIMO radar two dimensional angle estimation low-complexity propagator rectangular array

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Two-dimensional flow instability induced by natural convection in a square enclosure with four inner cylinders. Part II: Effect of various positions of inner cylinders

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INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2017年 113卷 1319-1331页

作者： Seo, Young Min Mun, Gi Su Park, Yong Gap Ha, Man Yeong Pusan Natl Univ Sch Mech Engn Jang Jeon 2 Dong Busan 609735 South Korea Rolls Royce Jang Jeon 2 Dong Busan 609735 South Korea Pusan Natl Univ Technol Ctr Thermal Management Jang Jeon 2 Dong Busan 609735 South Korea

Two-dimensional numerical simulations were conducted for the natural convection phenomena in a cold square enclosure containing four hot circular cylinders with Rayleigh number in the range of 10(3) <= Ra <= 10(6) and a Prandtl number of Pr = 0.7. The immersed boundary method (IBM) was used to capture the virtual wall boundary of the cylinders based on the finite volume method (FVM). In the present study, the variation in the vertical position of the cylinders was compared with those in the diagonal and horizontal positions. The change in the flow and thermal structures and corresponding heat transfer characteristics were investigated in regard to the transition of the flow regime from the steady state to the unsteady state at a relatively high Rayleigh number. In addition, the effects of the cylinder positions of a rectangular array in the square enclosure on the heat transfer characteristics are highlighted. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Natural convection Immersed boundary method Flow instability Four inner cylinders rectangular array Heat transfer

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