The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
R.h. Macphie - One of the best experts on this subject based on the ideXlab platform.
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Quasi-translational addition expressions of prolate scalar wave functions for thin prolate spheroids
IEEE Transactions on Antennas and Propagation, 1996Co-Authors: T. Do-nhat, R.h. MacphieAbstract:The conventional, translational addition theorems for both spherical and prolate Spheroidal wave functions applied to incoming or outgoing waves possess a well-known convergence sphere near which the addition series fail to converge rapidly. To overcome this deficiency the quasi-translational addition expressions for prolate wave functions are developed by using a physical-geometrical transformation which allows the separation in the azimuthal direction in the translated prolate Spheroidal Coordinate system. These quasi-translational addition expressions are valid everywhere and, in particular, exhibit a fast convergence characteristics for thin spheroids which are commonly used in physical and engineering applications.
T. Do-nhat - One of the best experts on this subject based on the ideXlab platform.
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Quasi-translational addition expressions of prolate scalar wave functions for thin prolate spheroids
IEEE Transactions on Antennas and Propagation, 1996Co-Authors: T. Do-nhat, R.h. MacphieAbstract:The conventional, translational addition theorems for both spherical and prolate Spheroidal wave functions applied to incoming or outgoing waves possess a well-known convergence sphere near which the addition series fail to converge rapidly. To overcome this deficiency the quasi-translational addition expressions for prolate wave functions are developed by using a physical-geometrical transformation which allows the separation in the azimuthal direction in the translated prolate Spheroidal Coordinate system. These quasi-translational addition expressions are valid everywhere and, in particular, exhibit a fast convergence characteristics for thin spheroids which are commonly used in physical and engineering applications.
Abdellatif Babaahmed - One of the best experts on this subject based on the ideXlab platform.
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unified analytical treatment of one electron two center integrals with noninteger n slater type orbitals
Theoretical Chemistry Accounts, 2000Co-Authors: Sidi Mohamed Mekelleche, Abdellatif BabaahmedAbstract:A unified treatment of one-electron two-center integrals over noninteger n Slater-type orbitals is described. Using an appropriate prolate Spheroidal Coordinate system with the two atomic centers as foci, all the molecular integrals are expressed by a single analytical formula which can be readily and compactly programmed. The analysis of the numerical performance of the computational algorithm is also presented.
Roger H Hackman - One of the best experts on this subject based on the ideXlab platform.
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Development and application of the Spheroidal Coordinate‐based T matrix to elastic wave scattering
Journal of the Acoustical Society of America, 1994Co-Authors: Roger H HackmanAbstract:A Spheroidal Coordinate‐based T‐matrix formalism is developed for the description of elastic wave scattering from a collection of obstacles embedded in a homogeneous, unbounded medium. The development of the Spheroidal formalism for the scattering from a single obstacle is based on the earlier work of Hackman [J. Acoust. Soc. Am. 75, 35–45 (1984)]; a discussion of the extension of this approach to a many‐inclusion system is a generalization of Lim and Hackman [J. Acoust. Soc. Am. 91, 613–638 (1992)]. Calculations are presented for the elastic wave scattering from (single) prolate Spheroidal and finite cylindrical objects and from both finite and infinite collections of spherical obstacles. The single inclusion calculations presented have bearing on a study of anechoic mechanisms in composite materials presented earlier [Lim and Hackman, J. Acoust. Soc. Am. 87, 1076–1103 (1990)].
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development and application of the Spheroidal Coordinate based t matrix to elastic wave scattering
Journal of the Acoustical Society of America, 1994Co-Authors: Roger H HackmanAbstract:A Spheroidal Coordinate‐based T‐matrix formalism is developed for the description of elastic wave scattering from a collection of obstacles embedded in a homogeneous, unbounded medium. The development of the Spheroidal formalism for the scattering from a single obstacle is based on the earlier work of Hackman [J. Acoust. Soc. Am. 75, 35–45 (1984)]; a discussion of the extension of this approach to a many‐inclusion system is a generalization of Lim and Hackman [J. Acoust. Soc. Am. 91, 613–638 (1992)]. Calculations are presented for the elastic wave scattering from (single) prolate Spheroidal and finite cylindrical objects and from both finite and infinite collections of spherical obstacles. The single inclusion calculations presented have bearing on a study of anechoic mechanisms in composite materials presented earlier [Lim and Hackman, J. Acoust. Soc. Am. 87, 1076–1103 (1990)].
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Development and application of the Spheroidal Coordinate based T matrix solution to elastic wave scattering
Radio Science, 1994Co-Authors: Roger H HackmanAbstract:A Spheroidal Coordinate based T matrix formalism is developed for the description of elastic wave scattering from a collection of obstacles embedded in a homogeneous, unbounded medium. The development of the Spheroidal formalism for the scattering from a single obstacle is a refinement of the earlier work of Hackman (1984), a discussion of the extension of this approach to a many inclusion system is a generalization of Lim and Hackman (1992). Calculations are presented for the elastic wave scattering from (single) prolate Spheroidal and finite cylindrical objects. The single inclusion calculations presented have bearing on a study of anechoic mechanisms in composite materials presented earlier (Lim and Hackman, 1990).
Alenka Zajic - One of the best experts on this subject based on the ideXlab platform.
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Geometric Analysis of the Doppler Frequency for General Non-Stationary 3D Mobile-to-Mobile Channels based on Prolate Spheroidal Coordinates
IEEE Transactions on Vehicular Technology, 1Co-Authors: Michael Walter, Dmitriy Shutin, Martin Schmidhammer, David W. Matolak, Alenka ZajicAbstract:Mobile-to-mobile channels often exhibit timevariant Doppler frequency shifts due to the movement of transmitter and receiver. An accurate description of the Doppler frequency turns out to be very difficult in Cartesian Coordinates, and any subsequent algebraic analysis of the Doppler frequency is intractable. In contrast to other approaches, we base our investigation on a geometric description of the Doppler frequency with the following three mathematical pillars: prolate Spheroidal Coordinate system, algebraic curve theory, and differential forms. The prolate Spheroidal Coordinate system is more appropriate to algebraically investigate the problem. After the transformation into the new Coordinate system, the theory of algebraic curves is needed to resolve the ambiguities. Finally, the differential forms are required to derive the joint delay Doppler probability density function. This function is normalized by the equivalent ellipsoidal area of the scattering plane bounded by the delay ellipsoid. The results generalize in a natural way our previous model to a complete 3D description. Our solutions enable insight into the geometry of the Doppler frequency and we were able to derive a Doppler frequency that is dependent on the delay and the scattering plane. The presented theory allows describing any time-variant, single-bounce, mobile-to-mobile scattering channel.